private async Task <Box> GetBox(BoxType boxType)
{
// get the box size
var size = await this.GetBoxSize(this.fileOffset);
// gets the box
var stream = await WebRequestor.GetStreamRangeAsync(this.fileUri, this.fileOffset, this.fileOffset + (long)size);
Box box = null;
using (var boxReader = new BoxBinaryReader(stream))
{
box = boxReader.ReadNextBox();
this.fileOffset += (long)size;
}
if (box.Type == boxType)
{
return(box);
}
else
{
return(await this.GetBox(boxType));
}
}
private static async Task <IList <Box> > GetBoxesAsync(Uri uri, WebRequestor.Range range)
{
using (var stream = await WebRequestor.GetStreamRangeAsync(uri, range))
{
using (var reader = new BoxBinaryReader(stream))
{
return(reader.GetAllBoxes());
}
}
}
private async Task <ulong> GetBoxSize(long position)
{
var stream = await WebRequestor.GetStreamRangeAsync(this.fileUri, position, position + 16);
using (var reader = new BoxBinaryReader(stream))
{
var size = this.ReadBoxSize(reader);
return(size);
}
}
private async Task <Box> GetNextBox()
{
var size = await this.GetBoxSize(this.fileOffset);
var boxStream = await WebRequestor.GetStreamRangeAsync(this.fileUri, this.fileOffset, this.fileOffset + (long)size);
Box box = null;
using (var boxReader = new BoxBinaryReader(boxStream))
{
box = boxReader.ReadNextBox();
this.fileOffset += (long)size;
}
return(box);
}
/// <summary>
/// Reads the header boxes for the video, which includes
/// ftyp, pdin, bloc, moov, and the optional mdat.
/// </summary>
/// <param name="callback"></param>
private async Task ReadMovieHeaderBoxes()
{
var moov = await this.GetBox(BoxType.Moov);
this.Boxes.Add(moov);
// See if we have an mdat next and grab it if we do
var stream = await WebRequestor.GetStreamRangeAsync(this.fileUri, this.fileOffset, this.fileOffset + 8);
using (var reader = new BoxBinaryReader(stream))
{
if (reader.PeekNextBoxType() == BoxType.Mdat)
{
var mdat = await this.GetNextBox();
this.Boxes.Add(mdat);
}
}
}
/// <summary>
/// This method of building the mfra will make web requests in order to download the data
/// from the online source.
/// </summary>
/// <param name="callback">The action that should be notified when the process is complete.</param>
private async Task ReadMovieFragmentRandomAccess()
{
#if !RANGESUFFIXSUPPORTED // not all backend services support range suffixes. For example, Azure Blobs. Here is a way around this but it requires an extra request to get the length and therefore does not perform as well.
var fileSize = await WebRequestor.GetFileSizeAsync(this.fileUri);
#endif
// grab the mfra offset
#if RANGESUFFIXSUPPORTED
var offsetStream = await WebRequestor.GetStreamRangeAsync(this.fileUri, -4);
#else
var offsetStream = await WebRequestor.GetStreamRangeNoSuffixAsync(this.fileUri, -4, fileSize);
#endif
uint mfraOffset = 0;
using (var reader = new BoxBinaryReader(offsetStream))
{
mfraOffset = reader.ReadUInt32();
}
// grab the mfra data
#if RANGESUFFIXSUPPORTED
var mfraStream = await WebRequestor.GetStreamRangeAsync(this.fileUri, -mfraOffset);
#else
var mfraStream = await WebRequestor.GetStreamRangeNoSuffixAsync(this.fileUri, -mfraOffset, fileSize);
#endif
// Write the bytes to our TOC file
using (var reader = new BoxBinaryReader(mfraStream))
{
reader.GotoPosition(0);
Box box = null;
do
{
box = reader.ReadNextBox();
if (box != null)
{
this.Boxes.Add(box);
}
} while (box != null);
}
}